Half-bridge resonant type DC-DC converters are used to implement constant current power supplies for use in light-emitting diode (LED) drivers and the like. In certain driver circuits, the half-bridge resonant type DC-DC converter is implemented as a second stage of a two-stage power system. The first stage of the two-stage power system is implemented as a rectifier that receives power from an AC source and by a power factor controller (PFC). The PFC receives the rectified output of the rectifier and provides a conditioned voltage to the input of the first stage. The PFC operates to reduce AC input current distortion. The PFC operates over a large load range; however, under very low conditions, the PFC may draw input current only during a portion of each AC cycle. When the input current turns off, noise may be generated, which may cause the second stage to introduce pulses in the load current on the output of the second stage. The pulses in the load current may introduce unwanted flickering in the light provided by the LEDs coupled to the output of the second stage.